The high performance of filed emission from well-aligned carbon nanotubes has been achieved by optimizing the thickness of an MgO coating layer on the nanotubes. It has been clarified that an MgO layer as thin as 2 nm degrades the emission properties and a thicker MgO layer does not improve the properties effectively. The most stable emission as low as 9% for 8 hrs with the lowest turn-on voltage of ∼116 V is obtained for the thickness of 10 nm. The 10 nm-MgO coated nanotubes also exhibit a uniform emission from the whole area of nanotubes. The theoretical calculation of the potential distribution around the emission sites supports the existence of this optimum thickness.
Yoshikazu Nakayama, Supriya Chakrabart, Lujun Pan, Yasumoto Konishi, Hiroyoshi Tanaka, "Field Emission with High Performance from MgO-Coated Carbon Nanotubes" in Proc. IS&T Int'l Conf. on Digital Printing Technologies (NIP22), 2006, pp 8 - 11, https://doi.org/10.2352/ISSN.2169-4451.2006.22.1.art00003_1